Conventionally, the manufacture of high modulus, high strength metal matrix composites in the aerospace industry is carried out in two major stages. In the first, monolayer tapes of high modulus, high strength brittle filaments of boron, silicon carbide or silicon carbide coated boron are sandwiched between a metal foil and a plasma sprayed metal coating, the metal being aluminum, magnesium or alloys thereof, by a winding and plasma spray operation as disclosed, for example, in U.S. Pat. No. 3,606,667 assigned to the present assignee. The second stage is the hot press diffusion bonding of multiple layers of these tapes to produce a multilayered composite. Typically, this stage requires the use of a vacuum hot press capable of providing high pressures generally in the range of 2,000-10,000 psi at elevated temperatures, usually 400.degree.-600.degree.C. This conventional diffusion bonding procedure requires bonding pressures in excess of 2,000 psi, a time cycle of several hours and an atmosphere of vacuum or inert gas. The lengthy time requirement is related to the practice of inserting the composite into the press prior to vacuum pump-down and heat-up and subsequent vacuum cooling after hot pressing. The heavy loading train plus dies generally require high powers and long times when they are enclosed in the vacuum system. The required time for heat-up bonding and cool-down to and from temperature, coupled with the magnitude of the pressures and temperatures needed for bonding can cause, in many cases, fiber degradation within the composite. In addition, the need for pressures on the order of 10,000 psi can unduly limit the size of the composite to be manufactured to the capacity of the hot press apparatus.
To overcome the limitations of diffusion bonding composites between fixed dies, the present invention, as described hereinafter, provides an inexpensive, essentially continuous and flexible procedure for the production of fully consolidated and bonded multilayered composites.